It is known that mineral matter contains metals which may be desirable and indeed the history of mankind has been a history of metallurgical processing, whereby various metals have been extracted from ores and the like. Man has also recognized that rock in its various forms may be utilized as a structural material and indeed as one of the first structural materials having been quarried or otherwise recovered from rock strata, shaped to the configuration desired and placed.
Up to now, however, if local rock was considered an advantageous material and could not economically be shaped as a solid object, the available alternatives for its use included incorporating the rock as an aggregate in a binder in the formation of concrete or the like.
The term "rock" is here used in its most common sense to refer to a material as extracted from an ore, which has not hitherto been generally viewed as a source of the components thereof. The term is thus used to denote stone and a material which consists of two or more minerals, generally with some substantial representation of silica or alumina, or both.
In various areas metal ores are not readily available, i.e. the metal is generally not a predominant component of the rock.
Furthermore, areas in which oxygen and water may be a necessity and also are not readily available exist and there have been some efforts to attempt to recover, for example, water from rock by intensive heating steps.